Mold for casting metals and process of making and using the molds



Federated May i923.

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HUBERT A. MYERS, OF TOLEDO, OHIO, ASSIGNOR TO THE HUBERT MYERS COMPANY,

OF TOLEDO, OHIO, A CORPORATION OF OHIO.

MOLD FOR CASTING METALS AND PROCESS OF MAKING AND USING THE HOLDS.

Ho Drawing.

To all whom it may concern:

Be it known that I, HUBERT A. MYERS, a citizen of the United States, and a resident of Toledo, in the county of Lucas and State of Ohio, have made an Invention Appertaming to Molds for Casting Metals and Processes of Making and Using the Molds; and I do hereby declare the following to be a full, clear, and exact description of the 1nvention, such as will enable others skilled 1n the art to which it appertains to make and use the same.

The object of my invention is to produce a mold that may be used for making repeated ferrous metal castings 1n rapid succession without adherence of the molten metal thereto and without the necessity of cooling, coating, or otherwise treating the mold to prevent such adherence. A further object of my invention is to produce, by the use of my lmproved mold, soft, easily machined ferrous metal castings having substantially uniform density and homogeneous structure throughout, and which will have approximately maximum tensile and mechanical strength.

My invention consists in forming the mold of materials containing one or more metals having melting points higher than the melting point of the metal to be cast therein. This prevents adherence of the casting to the mold, although the temperature of the mold may be raised to near a white heat. Thus the mold may he maintained at a relatively high temperature, thus preventing chilling of the casting and producing soft castings having no internal strains or stresses. The molds are particularly adapted-to the casting of ferrous metals commonly used in industrial work, such as iron, steel carrying different so-called impurities that modify their characteristics, not including chemically pure iron that has an unusually high melting point.

My molds are composed of materials containing nickel or cobalt, and, for want of a better broad term covering these metals, I shall refer to either or both of the metals broadly as nickel-cobalt metal. The nickelcobalt metal may be used in conjunction with other metals or with refractory materials, or alloys of nickel-cobalt metal may be used with refractory materials, or alloys Application filed March 80, 1921. Serial No. 457,085.

of nickel-cobalt metal with other metals may be used with refractory materials, or mixtures of nickel-cobalt metal and other metals may be used with refractories.

The mold may be formed entirely of nickel-cobalt metal, or of alloys of nickel and cobalt, or of alloys of one or both of these metals with copper, chromium, vanadium, or titanium, or With any number of these last mentioned metals. If alloys are used, the amount of the nickel-cobalt metal should exceed fifteen per cent and the proportion may be varied according to the temperature of the melting point of the particular metal with which it is alloyed, provided the melting point of the alloy is above the melting point of the metal to be cast. Alloys of n1ckel and chromium may be used in the proportion commonly found in-metals known in the trade as Chromel metal. Also alloys of nickel and .copper may be used in the proportions commonly found in metal known in the trade as Monel metal.

When an alloy is used for the mold, the proper selection of metals to be alloyed with the nickel-cobalt metal, and the proportions thereof, will be readily ascertainable by those skilled in the art, bearing in mind that the mold should be capable of withstanding high temperatures without fracture and of making repeated castings in rapid succession without adherence of the metal casting to the mold. The proportion of nickelcobalt metal that should be used depends upon the characteristics of the metals with which it is alloyed, and when used with brittle metals, such as chromium and vanadium, at least a sufiicient amount of nickelcobalt metal should be used to act as a binder for the other metals. When used with metals having a low melting point the nickel-cobalt metal should be used in suflicient amount to raise the melting point of the alloy above the melting point of the metal to be cast.

Molds containing refractory materials are so formed that the refractory is bonded by the metal. The refractory material may consist of any one or more of the well known refractories, such as refractory materials containing alumina as bauxite or silica, such as aluminum silicates, or a mixture of refractory materials that produce refractory silicates, or materials such as those containing calcium or magnesium such as magnesium aluminum silicates.

ere refractory materials are used in the mold I may use a nickel-cobalt metal, or an alloy of nickel-cobalt metal with any of the other metals, such as copper, chromium, vanadium, or titanium, which will produce the desired characteristics in the mold, namely, that will permit raising the mold to a high temperature without fracture and will prevent adherence of the metal casting to the mold. The melting point of the metal in the mold should be above that of the metal to be cast and the fusing point of the refractory should at least be as high as that of the metal of the mold. If desired, I may add fluxes to the ceramic mixture to vary the fusing point of the refractories, or mixtures of refractories may be used, or both fluxes and mixtures of refractories ma, be used, to vary the fusing point of the re ractory materials whereby plasticity of the heated refractory is controlled. The plasticity may thus be brought about at or slightly above the melting point of the metal or alloy of metals mixed with the refractories. Moreover, the alloys may be formed so as to vary the melting point of the metal relative to the fusing point of the refractor 1 1 1 making up the molds containing the refractory materials and a metal, or alloy of metals, or metals unalloyed, I preferably mix the ingredients in a more or less finely divided state and then subject them to a temperature sufficient to cause not only calcination of the refractory material and bond ing by the glassy matrix formed thereon, but also to fuse the metal so that the refractory will also be thoroughly bonded by the metal, when cooled. While the mass is in a heated condition, it is molded into form. While still in a plastic condition, and in the mold, it may be subjected to pressure and then allowed to cool slowl'yin order that distortion by reason of shrinkage may be obviated or greatly lessened. This results in an exceedingly hard body having great tensile strength and one not easily broken by heat or mechanical stresses or shocks.

In forming the molds, I find that it is preferable to use a fine grade of fire clay as the refractory material, mixed with nickel. 15% or more of nickel and the balance of clay may be used. The nickel, in a finely divided or a eomminuted state, is thoroughly mixed with powdered clay. Water is then added to the clay until it is a plastic mass. The mass is molded to form and the forms are allowed to dry slowly. The molds are then heated to a temperature sufiicient to melt the metal and cause plasticity or moldability of the clay. They are then placed in iron forms or molds and allowed to cool slowlyand preferably subjected to high pressure, which prevents deformation of the mold.

In casting the ferrous metals, the mold is preferably raised to a relatively high temperaturc, such as cherry red, and the fer-- rous metal is poured into the mold and immediately upon slight congealing of the metal the casting is discharged and the ferrous metal is again poured into the mold. Rapid casting of the articles will maintain the mold at a relatively high temperature without additional heat from other sources.

If desired, lamp black or plumbago or other temporary facing material may be used to coat the molds, in order to give the castings in smooth surface and assist in the ready withdrawal thereof from the mold, particularly when relative tangential or parallel movements of surfaces of the casting and the mold are involved. Also if the mold contains iron in metallic form, the use of a protective coating or surfacing material will be found desirable to prevent adherence of the castings to the mold.

I claim 1. In a mold for casting metals, the mold formed of ingredients comprising a nickel cobalt metal.

2. In a mold for casting metals, the mold formed of ingredients comprising nickel.

3. In a mold for casting metals formed of ingredients comprising a nonferrous metal having a fusing point above 1350 C.

4. In a mold for casting metals formed of ingredients comprising a nonferrous alloy having a fusing point above 1350 C.

5. In a mold for casting metals, the mold containing a metal alloy comprising a nickel cobalt metal,

6. In a mold for casting metals, the material of the mold comprising a mixture of metallic and ceramic refractory material.

7. In a mold for casting metals, the material of the mold comprising a mixture of metallic and ceramic refractory materials and silica.

8. In a mold for casting metals, the mold consisting of nickel and a ceramic refractory material.

9. In a mold for casting metals, the mold containing nickle-cobalt metal and a ceramic refractory material.

10. In a mold for casting metals, the mold containing an alloy of nickel-cobalt metal with another metal and a ceramic refractory material.

11. In a mold for casting metals,the mold containing a metal and a ceramic refractory material, the fusing point of the metal of the mold being above 14:00 C. and at least as low as the temperature at which the refractory material will become plastic.

12. In a mold for casting metals, the mold containing a metal and a ceramic refractory material, the fusing point of the metal of the mold having a melting point above W 6., the refractory material having a fusing point about that of the melting point of the metal of the mold.

13. in a mold for casting metals, the mold containing a metal and a ceramic refractory material, the refractory material having a fusing point at least as high as that of the melt-in point of the metal of the mold.

14:. n a mold for casting metals, a mold containing a mixture of nickel and ceramic refractory material, the refractory material having a fusing point at least as high as that of the nickel.

15. in a mold for casting metals, the mold containing an alloy of nickel-cobalt metal with another metal and a ceramic refractory material, the metal of the mold having a fusing point above that of the metals to be cast.

16. In a mold for casting metals, a mold containing a mixture of nickel alloyed with another metal and ceramic refractory material, the refractory material having a fusing pziint at least as high as that of the nickel al 0 1% In a mold for casting metals, the mold consisting of nickel and calcined clay.

18. In a mold for casting metals, the mold consisting of nickel and calcined clay having a fusing point at least as high as that of the nickel.

19. In a mold for casting metals, the mold containing nickel alloyed with another metal and clay, the clay having a fusing point at least as high as that of the nickel alloy.

20. The process of makin molds which consists in mixing a finely divided metal with a refractory, molding the mass into form and heating the mixture to cause fusion of the metal and plasticity of the refractory.

21. The process of making molds, which consists in mixing a finely divided metal with a refractory having a fusing point at least as high as that of the metal and heating the mixture to cause a fusion of the metal and the refractory, and compressing the plastic mass in a mold.

of the mixture having a fusing point that is at least as high as the highest fusing point of the metals, and heating the mixture until plastic.

24. The process of forming molds, which consists .in mixing an alloy of metals and refractory materials, the portion of the mixture consisting of refractory materials hav ing a fusing point at least as high as that of the alloy, heating the mixture to reduce the mass to a plastic condition and molding the mass.

25. The process of forming molds, which consists in mixing an alloy of metals and a mixture of a ceramic refractory material, the alloy and the refractory materials having substantially the same fusing points, heating the mixture to reduce the mass to a plastic condition, and subjecting the mass to pressure. 

